When thermal imagers arrived on scene they were quickly welcomed but only a handful of agencies could overcome the large dose of sticker shock. Most agencies were fast to recognize the benefits but couldn’t afford the price tag and haven’t revisited the whole idea getting thermal imagers in their arsenal. If you or your agency falls into the latter group…read on, I’ll bring you up to speed with advancements that make thermal useful for nearly every function in law enforcement and debunk a few myths along the way.


By far, the biggest advancement of thermal is the decreased price. Just as recent as two years ago, an agency wishing to equip a patrol car with thermal would pay around $20k. Today, that same agency can buy a turn-key package starting at as little as $2,500. There has been such a huge drop in price that, in some cases, thermal imagers are even being used in lieu of traditional security cameras. With lower prices and grants, which promote thermal technology, equipping an entire fleet is now viably possible, especially when the benefits are factored.

Pursuit and Retrieval

Seasoned officers will be the first to tell you that fleeing criminals are easily lost especially when a foot chase ensues at night. Thermal imagers bring a dramatic shift to the odds in favor of law enforcement. A suspect hiding in the night shadows of a backyard, brush or field will be seen clear as day when an officer peers through a thermal imager. In cases where the suspect has taken refuge inside of a structure, today’s thermal imagers are sensitive enough to see the trail of footsteps and hand prints leading right to the suspect, even minutes later.

Catching a crook is one thing, but sometimes collecting crucial evidence that may have been tossed is another. Thermal imagers come in quite handy when searching for abandoned items such as guns, knives, dope bags and stolen property making them readily seen even on the darkest night. One of the top imagers available is FLIR’s FlashSight. The FlashSight is a handheld unit that is built tough enough to definitely be considered “cop-proof”, uses normal alkaline batteries and is easy to manage even while wearing gloves. Once evidence is spotted using the FlashSight, a quick tap on the photo button will record a digital image which can later be downloaded via USB.

Surveillance and Swat

Even when equipped with NVGs or active IR cameras on surveillance missions, suspects are easily lost or sometimes never found because of their lack of motion. Conversely, suspects moving or standing still are easily targeted with thermal. Suspects body temperature makes them stick out like sore thumbs and are very easy to locate.

It’s certainly unfortunate but true that law enforcement are not the only ones with surveillance tools. The bad guys are getting geared up these days to provide security for their so called “livelihood” which entails watching out for law enforcement. This can pose a great challenge to law enforcement when discrete surveillance or entrance to the property is needed. An aid to counter this is thermal technology. Thermal imagers can be used to detect surveillance cameras which thankfully produce a healthy amount of heat and will be a glow when spotted through thermal imagers. Once the security cameras have been spotted, they can then be smartly avoided.

Thermal imagers can also be weapon borne which is an added advantage over normal thermal devices. One weapon borne thermal imager is FLIR’s ThermoSight. The ThermoSight is built in the same form-factor as the FlashSight and is packed with the same capabilities. However, the ThermoSight has reactive cross-hairs built-in which makes targeting simple and fast. As soon as the cross-hairs intersect with a warm-blooded target, they change colors.

Officer and Public Safety

Flashlights used to illuminate fleeing suspects are without a doubt trusted tools, but they also make officers easy to spot and sadly easy to sight in. With thermal imagers, officers can not only gain the advantage of seeing the suspect long before the suspect sees them, but the officers are no longer a glowing target. To protect officers even further, I highly recommend thermal imagers with collapsing eye-cups that conceal the view-finder of the thermal imager until the officer presses their eyes against the view-finder.

The same benefits of thermal and concerns about visible illumination applied to officer safety can also be applied to patrol vehicles. Patrol vehicles in search of suspects with high powered alley-lights most definitely alert bad guy where not to run and can additionally make the vehicle an easy target for gunfire. Officers operating vehicles equipped with thermal imaging can, in many cases, disable normal illumination and rely solely on thermal imaging to minimize detection and increase the odds of apprehension.

Patrol officers have a lot to take in, and they need every driving advantage possible. Vehicles equipped with thermal will deliver some huge advantages such as the ability to see obstructions or pedestrians 4X further than normal headlights. Bad weather is never a recipe for a day off from patrol or responding to calls. On inclement weather days, thermal provides an additional benefit of penetrating through fog and rain, which is very comforting when every second counts.

The same features of thermal that keep officers safe and aid in the apprehension of criminals can also be used in rescue situations. Without the use of thermal, a person lost in the wilderness or treading in a vast expanse of water is pretty easy to miss. Like suspects, the innocent will fortunately stick out like sore thumbs when thermal imagers are in play.


Thermal imagers can’t be used during the day!

There is a common myth that thermal imagers are not effective during daytime hours. I believe this myth is largely the result of experiences with night vision devices such as light intensifiers a.k.a. NVGs (Night Vision Goggles). Light intensifiers do just what they say, they intensify light which make them useful at night but useless during the day. In fact, many NVG will be permanently useless if an attempt is made to use them during the day without special testing filters that help block light. Thermal imagers on the other hand, don’t use light to produce images, they use heat and can easily discern between the faintest of temperature differences. So during the day thermal imagers offer the same benefits and there is no risk of damage.

Thermal imagers have a short life!

As I mentioned earlier, thermal imagers are being used to replace security cameras in typically defense orientated applications where superior detection of targets is extremely critical. Unlike light intensifiers, thermal imagers have no tube to burn out. Thermal imagers are constructed in a similar fashion to modern security cameras and are made for years of non-stop service.

Maintenance and batteries are too expensive!

Can you clean a camera lens? If so, you can maintain a thermal imager. Maintenance is easy, there is just simply not a lot to take care of other than to keep it clean and use it. As example, the FLIR PathFindIR is constructed to withstand the punishment of being mounted to the grill-work of a patrol car… that’s tough. When it comes to battery powered units, many thermal imagers just need normal AA batteries, but if you want, you can easily use the slightly higher priced lithium batteries for additional run time.

Our agency can’t afford thermal!

Ok, there may be some truth to this, as there never seems to be enough funding. However, prices have truly dropped enormously and there is free money floating around just waiting for your agency to grab it. To get a grant, here is a good place to start.

Demo and Help

If you are convinced that thermal is the next “got to have it” tool but you want to take it for a test drive or you need convince someone else first, send me an email and I’ll be happy to send one out on loan. Likewise, if you have any further questions or comments please let us know at [email protected].

{{widget type=”cms/widget_block” template=”cms/widget/static_block/default.phtml” block_id=”155